JP5979923B2 - Coating agent, coating film and laminate - Google Patents

Description

  The present invention relates to a coating agent containing a polyester resin, a bis (2-oxazoline) compound and an organic solvent. Furthermore, this invention relates to the coating film formed from this coating agent, and the laminated body containing this coating film.

  Polyester resins typified by polyethylene terephthalate and polybutylene terephthalate are excellent in mechanical strength, thermal stability, hydrophobicity and chemical resistance. Therefore, it is widely used in various fields as a material for a molded article such as a fiber or a film or a sheet.

  In the polyester resin, it is possible to obtain a polyester resin having various structures and characteristics by changing the types of dicarboxylic acid and glycol as constituent components. Such polyester resins are widely used as coating agents and adhesives. Furthermore, such coating agents and adhesives made of polyester resin generally have excellent adhesion to substrates made of polyester resin, polycarbonate resin, polyvinyl chloride, or metal foils such as aluminum and copper. For example, it is widely used in the field of flexible flat cables and optical panels widely used as wiring materials for digital home appliances or automobiles.

  However, when such a coating agent composed of a polyester resin is used in a very severe environment such as high temperature and high humidity, the molecular weight of the polyester resin decreases with time due to hydrolysis. There was a problem that it was inferior in chemical properties and wet heat durability. Therefore, a coating agent using a resin other than a polyester resin has been studied. In that case, the adhesion to a substrate such as a polyester film or a metal deposition layer (metal or metal oxide deposition layer) is extremely low. There was a problem that only things could be obtained.

  In view of such problems, in order to obtain a coating agent in which a decrease in molecular weight over time is suppressed even when a polyester resin is used, polyalkylene glycol is contained as a glycol component constituting the polyester resin, and this A copolyester resin in which the molecular weight of repeating units of polyalkylene glycol is controlled within a specific range has been proposed (Patent Document 1). However, the coating agent comprising the polyester resin described in Patent Document 1 is inferior in storage stability because the pot life (the time until the viscosity and state of the coating agent cannot withstand use) is short, and is still inferior. There is a problem that it is inferior in wet heat durability.

JP 2001-200041 A

  That is, in the prior art, a coating agent that has excellent adhesion to a substrate and, in addition, excellent storage stability and wet heat durability has not yet been obtained.

  The present invention is intended to solve the above-mentioned problems, and it is a technical problem to obtain a coating agent that is excellent in adhesion to a substrate and in addition, excellent in storage stability and wet heat durability. .

なお、式（Ｉ）中、ｎは２〜３６の整数であり、ｍは２〜２００の整数である。
（ｉｉ）ポリエステル樹脂の重量平均分子量が１００００を超え４００００以下である。
（ｉｉｉ）ポリエステル樹脂のガラス転移温度が−３５℃以上５０℃未満である。
（ｉｖ）ポリエステル樹脂の酸価が３５〜８９５当量／トンである。
（ｖ）ポリエステル樹脂の酸価に対するビス（２−オキサゾリン）化合物のオキサゾリニル残基の当量比が０．８〜２．０倍当量である。
（ｖｉ）ポリエステル樹脂、ビス（２−オキサゾリン）化合物および有機溶剤の含有割合が、質量比で、［ポリエステル樹脂＋ビス（２−オキサゾリン）化合物］／（有機溶剤）＝５／９５〜５０／５０である。 The present inventor has reached the present invention as a result of intensive studies to solve the above problems.
That is, the gist of the present invention is as follows.
(1) A polyester resin, a bis (2-oxazoline) compound, and an organic resin comprising a dicarboxylic acid component and a glycol component as main components and an aromatic dicarboxylic acid copolymerized in a proportion of 60 mol% or more with respect to the total carboxylic acid component. A coating agent comprising a solvent and satisfying the following (i) to (vi) simultaneously:
(I) The polyester resin contains 2 to 30 mol% of a polyoxyalkylene glycol having a molecular weight of 200 to 2000 represented by the following formula (I) as a glycol component.

In formula (I), n is an integer of 2 to 36, and m is an integer of 2 to 200.
(Ii) The weight average molecular weight of the polyester resin is more than 10,000 and not more than 40,000.
(Iii) The glass transition temperature of the polyester resin is −35 ° C. or higher and lower than 50 ° C.
(Iv) The acid value of the polyester resin is 35 to 895 equivalent / ton.
(V) The equivalent ratio of the oxazolinyl residue of the bis (2-oxazoline) compound to the acid value of the polyester resin is 0.8 to 2.0 times equivalent.
(Vi) The content ratio of the polyester resin, the bis (2-oxazoline) compound and the organic solvent is [polyester resin + bis (2-oxazoline) compound] / (organic solvent) = 5/95 to 50/50 by mass ratio. It is.

(2 ) A coating film characterized by being formed from the coating agent of ( 1 ) .
( 3 ) A laminate comprising a substrate and the coating film of ( 2 ).

  According to the present invention, the equivalent ratio of the oxazolinyl residue of the bis (2-oxazoline) compound to the weight average molecular weight, the acid value of the polyester resin used and the acid value of the polyester resin is set to a specific range at the same time. In addition to excellent adhesion to the substrate, good adhesion can be maintained even after hot water treatment, chemical treatment and wet heat treatment (ie, excellent hot water resistance, chemical resistance and wet heat durability) Furthermore, the coating agent which is excellent also in storage stability can be provided. And the coating film formed from this coating agent can be used suitably also as a protective film at the time of providing a metal vapor deposition layer, the primer for vapor deposition films, or the adhesive agent of various layers.

なお、式（Ｉ）中、ｎは２〜３６の整数であり、ｍは２〜２００の整数である。
（ｉｉ）ポリエステル樹脂の重量平均分子量が１００００を超え４００００以下である。
（ｉｉｉ）ポリエステル樹脂のガラス転移温度が−３５℃以上５０℃未満である。
（ｉｖ）ポリエステル樹脂の酸価が３５〜８９５当量／トンである。
（ｖ）ポリエステル樹脂の酸価に対するビス（２−オキサゾリン）化合物のオキサゾリニル残基の当量比が０．８〜２．０倍当量である。
（ｖｉ）ポリエステル樹脂、ビス（２−オキサゾリン）化合物および有機溶剤の含有割合が、質量比で、［ポリエステル樹脂＋ビス（２−オキサゾリン）化合物］／（有機溶剤）＝５／９５〜５０／５０である。 Hereinafter, the present invention will be described in detail.
The coating agent of the present invention comprises a polyester resin, bis (2-oxazoline), which contains a dicarboxylic acid component and a glycol component as main components and an aromatic dicarboxylic acid copolymerized in a proportion of 60 mol% or more with respect to the total carboxylic acid component. ) A compound and an organic solvent are contained, and the following (i) to (vi) are satisfied at the same time.
(I) The polyester resin contains 2 to 30 mol% of a polyoxyalkylene glycol having a molecular weight of 200 to 2000 represented by the following formula (I) as a glycol component.

In formula (I), n is an integer of 2 to 36, and m is an integer of 2 to 200.
(Ii) The weight average molecular weight of the polyester resin is more than 10,000 and not more than 40,000.
(Iii) The glass transition temperature of the polyester resin is −35 ° C. or higher and lower than 50 ° C.
(Iv) The acid value of the polyester resin is 35 to 895 equivalent / ton.
(V) The equivalent ratio of the oxazolinyl residue of the bis (2-oxazoline) compound to the acid value of the polyester resin is 0.8 to 2.0 times equivalent.
(Vi) The content ratio of the polyester resin, the bis (2-oxazoline) compound and the organic solvent is [polyester resin + bis (2-oxazoline) compound] / (organic solvent) = 5/95 to 50/50 by mass ratio. It is.

  In the coating agent of the present invention, by satisfying the above (i) to (vi) at the same time, it is excellent in adhesion to various substrates when it is formed into a coating film, hydrothermal treatment, chemical treatment and wet heat treatment. Even after being applied, cracks do not appear and adhesion is maintained, and in addition, a remarkable synergistic effect is exhibited that storage stability is excellent.

  First, the polyester resin used in the present invention will be described. The polyester resin is composed mainly of a dicarboxylic acid component and a glycol component. The main component means that the ratio of components other than the dicarboxylic acid component and the glycol component in the polyester resin is less than 20 mol%.

  Dicarboxylic acids constituting the dicarboxylic acid component include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, naphthalene dicarboxylic acid, 5-sodium sulfoisophthalic acid; oxalic acid, malonic acid, succinic acid, glutaric acid, Adipic acid, sebacic acid, pimelic acid, suberic acid, azelaic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, heptadecanedioic acid, octadecanedioic acid, nonadecanedioic acid , Eicosandioic acid, docosandioic acid, fumaric acid, maleic acid, itaconic acid and other aliphatic dicarboxylic acids, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, perhydro Naphthalenedicarboxylic acid, die Over acid, alicyclic dicarboxylic acids such as cyclobutene dicarboxylic acid. These may be anhydrides.

  Especially, as a dicarboxylic acid component, it is preferable to use aromatic dicarboxylic acid from a viewpoint of the adhesiveness (adhesiveness) with respect to the base material of the coating agent obtained. Furthermore, in the present invention, it is preferable to use a polyester resin in which the copolymerization ratio of the aromatic dicarboxylic acid is 60 mol% or more with respect to the total amount of the dicarboxylic acid component, and the copolymerization ratio is 80 mol% or more. It is more preferable to use a polyester resin. If the copolymerization amount of the aromatic dicarboxylic acid is less than 60 mol%, the glass transition temperature of the polyester resin may decrease (that is, the glass transition temperature will be less than -35 ° C). The resulting coating agent is not preferred because the chemical resistance and hot water resistance when it is used as a coating film are reduced.

  As a glycol constituting the glycol component, a polyoxyalkylene glycol having a molecular weight of 200 to 2000 represented by the above formula (I) may be copolymerized in a proportion of 2 to 30 mol% in all glycol components. It is necessary, it is preferable that it is 5-25 mol%, and it is more preferable that it is copolymerized in the ratio of 10-20 mol%. By satisfying such a constituent requirement, in the present invention, a coating agent remarkably excellent in wet heat durability can be obtained. If the copolymerization ratio is less than 2 mol%, there is a problem that the wet heat durability of the polyester resin is insufficient. On the other hand, if the copolymerization ratio exceeds 30 mol%, the solubility of the polyester resin in an organic solvent is lowered, or the pot life after dissolving in a solvent is shortened and the storage stability is lowered.

  As described above, the molecular weight (weight average molecular weight) of polyoxyalkylene glycol needs to be 200 to 2000, and preferably 600 to 2000. When the molecular weight of the polyoxyalkylene glycol is less than 200, there is a problem that sufficient wet heat durability cannot be obtained. On the other hand, when the molecular weight exceeds 2000, the pot life after dissolving the polyester resin in the solvent is shortened, and the storage stability is lowered, which is not preferable.

In addition, from the viewpoint of setting the molecular weight of the polyoxyalkylene glycol in the above range, in the formula (I), n needs to be an integer of 2 to 36, and preferably an integer of 10 to 36. Moreover, m needs to be an integer of 2 to 200, and preferably represents an integer of 10 to 150.

  Examples of the polyoxyalkylene glycol include polyethylene glycol, polytetramethylene glycol, polypropylene glycol, polyhexylene glycol, polynonanediol, poly (3-methyl-1,5-pentane) diol, and the like.

  As glycols other than polyoxyalkylene glycol constituting the glycol component, ethylene glycol, propylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1 , 12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,15-pentadecanediol, 1,16-hexadecanediol, 1,17-heptadecanediol, 1,18-octadecanediol, 1,19-nonadecanediol, 1,20-d Cosanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 2,2-diethyl-1,3-propanediol, 2-ethyl-2-butyl-1,3-propanediol, diethylene glycol, triethylene Glycol, dipropylene glycol, tripropylene glycol, 2,2,4-trimethyl-1,3-pentanediol, 1,4-cyclohexanediol, spiroglycol, 1,4-phenylene glycol, 1,4-phenylene glycol ethylene Examples thereof include an oxide adduct and a propylene oxide adduct of 1,4-phenylene glycol.

  In addition, a hydroxycarboxylic acid may be copolymerized with the polyester resin, if necessary, within a range not impairing the effects of the present invention. Hydroxycarboxylic acids include lactic acid, glycolic acid, 2-hydroxybutyric acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-hydroxyisobutyric acid, 2-hydroxy-2-methylbutyric acid, 2-hydroxyvaleric acid, 3-hydroxy Hydroxycarboxylic acids such as valeric acid, 4-hydroxyvaleric acid, 5-hydroxyvaleric acid, 6-hydroxycaproic acid, 10-hydroxystearic acid, 4- (β-hydroxy) ethoxybenzoic acid; β-propiolactone, β And aliphatic lactones such as -butyrolactone, γ-butyrolactone, δ-valerolactone, and ε-caprolactone. When hydroxycarboxylic acid is copolymerized with the polyester resin, the copolymerization ratio of hydroxycarboxylic acid is 20 mol% or less with respect to all dicarboxylic acid components constituting the polyester resin from the viewpoint of not forming an excessively large block polymer. It is preferable that

  In addition, the polyester resin may be copolymerized with a monocarboxylic acid, a monoalcohol, a trifunctional or higher carboxylic acid, a trifunctional or higher alcohol, etc., as long as the amount is small.

  Examples of monocarboxylic acids include benzoic acid, phenylacetic acid, lauric acid, palmitic acid, stearic acid, oleic acid and the like. Examples of the monoalcohol include cetyl alcohol, decyl alcohol, lauryl alcohol, myristyl alcohol, octyl alcohol, stearyl alcohol and the like. Examples of the trifunctional or higher functional carboxylic acid include trimellitic acid, trimesic acid, and pyromellitic acid. Examples of the tri- or higher functional alcohol include trimethylolethane, trimethylolpropane, glycerin, pentaerythritol, α-methylglucose, mannitol, sorbitol and the like. These copolymerization ratios are preferably 0.2 to 20 mol% with respect to the total dicarboxylic acid component and the total glycol component, respectively.

  The weight average molecular weight of the polyester resin needs to be more than 10,000 and 40000 or less, preferably 12000 to 38000, and more preferably 15000 to 35000. Chemical resistance falls that the weight average molecular weight of a polyester resin is 10,000 or less. On the other hand, when the weight average molecular weight of the polyester resin exceeds 40,000, the solubility of the polyester resin in the organic solvent is lowered, so that it is difficult to obtain the coating agent itself.

  Examples of the method for controlling the weight average molecular weight of the polyester resin within the above range include the following methods. That is, a method of terminating the polymerization when the viscosity of the polyester resin reaches a predetermined range (for example, when the melt viscosity becomes about 10 to 1000 Pa · s); a depolymerizer after producing a polyester resin having a high molecular weight And a method of reducing the molecular weight; a method of adding a monoalcohol or a monocarboxylic acid when charging the raw material monomer. Among these, from the viewpoint of efficient production, a method of terminating the polymerization when the viscosity of the polyester resin falls within a predetermined range is preferable.

  The glass transition temperature (sometimes referred to as “Tg” in this specification) of the polyester resin needs to be −35 ° C. or higher and lower than 50 ° C., preferably −35 to 45 ° C., − It is more preferable that it is 25-40 degreeC. If the glass transition temperature of the polyester resin is less than -35 ° C, it will not be solidified even at room temperature, making it extremely difficult to handle and not suitable for practical use. Moreover, even if a coating agent is obtained, when it is used as a coating film, it is inferior to hot water resistance, chemical resistance, and wet heat durability. On the other hand, when the glass transition temperature of the polyester resin is 50 ° C. or higher, the solubility of the polyester resin in the organic solvent is lowered, and thus it is difficult to obtain the coating agent itself. Moreover, even if a coating agent is obtained, when it is used as a coating film, it becomes inferior to wet heat durability.

  In order to control the glass transition temperature of the polyester resin within the above range, a method of appropriately selecting a raw material monomer component to be copolymerized and a copolymerization ratio thereof can be employed.

  The acid value of the polyester resin needs to be 35 to 895 equivalent / ton, preferably 50 to 880 equivalent / ton, and more preferably 60 to 860 equivalent / ton. When the acid value of the polyester resin is less than 35 equivalents / ton, the adhesion of the resulting coating agent is lowered. On the other hand, when it exceeds 895 equivalent / ton, there exists a problem that hot water resistance, chemical resistance, and wet heat durability fall.

  Examples of the method for controlling the acid value of the polyester resin include the following methods. That is, a method in which a polymerization reaction is allowed to proceed until the weight average molecular weight of the polyester resin exceeds a desired range, and then a polyfunctional carboxylic acid as a depolymerizing agent is appropriately added for depolymerization; Examples include a method of adjusting the molar ratio of the acid component and the glycol component; Among these, from the viewpoint that the molecular weight and acid value can be stably adjusted, the polymerization reaction is allowed to proceed until the molecular weight of the polyester resin exceeds the desired range, and then a polyfunctional carboxylic acid is added as appropriate. The depolymerization method is preferred.

  Examples of the production method for obtaining the polyester resin used in the present invention include known production methods such as a direct esterification method and a transesterification method.

  Examples of the direct esterification method include a method in which a necessary raw material monomer is injected into a reaction vessel, an esterification reaction is performed, and then a polycondensation reaction is performed. The esterification reaction is performed by heating and melting at a temperature of 180 ° C. or higher for 4 hours or more in a nitrogen atmosphere. In the polycondensation reaction, the polycondensation reaction proceeds under a reduced pressure of 130 Pa or less at a temperature of 220 to 280 ° C. until a desired molecular weight is reached.

In the esterification reaction and polycondensation reaction, a catalyst for facilitating the reaction may be used. Examples of the catalyst include titanium compounds such as tetrabutyl titanate; acetates of metals such as zinc acetate and magnesium acetate; organotin compounds such as antimony trioxide, hydroxybutyltin oxide, and tin octylate. The amount of the catalyst is not particularly limited, the acid component per mol, preferably in a 0.1 × ^{10 -4} ~100 × ¹⁰ -4 mol.

Next, the bis (2-oxazoline) compound will be described.
In the present invention, the bis (2-oxazoline) compound is contained as a crosslinking agent. By using a bis (2-oxazoline) compound as a cross-linking agent, the resulting coating agent is cured at a temperature lower than the softening point of a resin generally used as a base material such as a polyester resin or a polypropylene resin. Can do. Therefore, the polyester resin can be crosslinked without deteriorating the substrate, and as a result, a tough coating film can be formed even if the curing temperature is low. When a cross-linking agent other than a bis (2-oxazoline) compound is used, the cross-linking with the polyester resin does not proceed sufficiently, resulting in poor hot water resistance, chemical resistance and wet heat durability. There is a problem that only a coating agent can be obtained.

The bis (2-oxazoline) compound is represented by the following formula (II).

Here, R ₁ , R ₂ , R ₃ and R ₄ each represent hydrogen, an alkyl group or an aryl group. R represents an intercarbon bond or a divalent hydrocarbon group. Examples of the alkyl group represented by R ₁ , R ₂ , R ₃ or R ₄ include a methyl group, an ethyl group, and a propyl group. Examples of the aryl group include a phenyl group and a tolyl group. Examples of the hydrocarbon group represented by R include arylene groups such as alkylene groups having 2 to 8 carbon atoms, cycloalkylene groups having 3 to 8 carbon atoms, phenylene groups, and tolylene groups.

Of these, the group represented by R ₁ , R ₂ , R ₃ or R ₄ is preferably an alkyl group or an aryl group. The group represented by R is preferably an arylene group having 3 to 8 carbon atoms.

  Specific examples of the bis (2-oxazoline) compound used in the present invention include, for example, 2,2′-bis (2-oxazoline), 2,2′-bis (4-methyl-2-oxazoline), 2 , 2′-bis (5-methyl-2-oxazoline), 2,2′-bis (5,5′-dimethyl-2-oxazoline), 2,2′bis (4,4,4 ′, 4′- Tetramethyl-2-oxazoline), 1,2-bis (2-oxazolin-2-yl) ethane, 1,4-bis (2-oxazolin-2-yl) butane, 1,6-bis (2-oxazoline-) 2-yl) hexane, 1,8-bis (2-oxazolin-2-yl) octane, 1,4-bis (2-oxazolin-2-yl) cyclohexane, 1,2-bis (2-oxazolin-2-) Yl) benzene, 1,3-bis (2-o Sazolin-2-yl) benzene, 1,4-bis (2-oxazolin-2-yl) benzene, 1,2-bis (5-methyl-2-oxazolin-2-yl) benzene, 1,3-bis ( 5-methyl-2-oxazolin-2-yl) benzene, 1,4-bis (5-methyl-2-oxazolin-2-yl) benzene, 1,4-bis (4,4′-dimethyl-2-oxazoline) -2-yl) benzene, 1,4-bis (2-benzoxazolyl) naphthalene, 1,4-bis [2- (5-phenyloxazolyl)] benzene, 2,5-bis (5-t-butyl- 2-benzoxazolyl) thiophene and the like. Of these, from the viewpoint of general availability, 1,3-bis (2-oxazolin-2-yl) benzene, 1,4-bis (2-oxazolin-2-yl) benzene, 1,4-bis (2 -Benzoxazolyl) naphthalene, 1,4-bis [2- (5-phenyloxazolyl)] benzene, 2,5-bis (5-tert-butyl-2-benzoxazolyl) thiophene are preferred, -Bis (2-oxazolin-2-yl) benzene is particularly preferred.

  In this invention, a crosslinking catalyst can be used as needed with the bis (2-oxazoline) compound which is a crosslinking agent. By using a crosslinking catalyst, when a coating film is obtained from the coating agent of the present invention, crosslinking can be performed more efficiently.

  As the crosslinking catalyst, sulfonic acid is preferable, for example, inorganic sulfonic acids such as sulfuric acid and sulfonic acid; methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, decanesulfonic acid, benzenesulfonic acid, o-toluenesulfonic acid, m-toluene. Examples thereof include organic sulfonic acids such as sulfonic acid, p-toluenesulfonic acid, naphthalenesulfonic acid, xylenesulfonic acid, and dodecylbenzenesulfonic acid. Of these, p-toluenesulfonic acid and dodecylbenzenesulfonic acid are preferred, and p-toluenesulfonic acid is particularly preferred from the viewpoint of keeping the pot life long.

The composition of the coating agent of the present invention will be described below.
In the coating agent of the present invention, the content ratio of the polyester resin, the bis (2-oxazoline) compound and the organic solvent is such that [total amount of the polyester resin and bis (2-oxazoline) compound] / (organic solvent) is a mass ratio. And 5/95 to 50/50, and preferably 10/90 to 40/60. Obtained when the total amount of the polyester resin and the bis (2-oxazoline) compound is less than 5% by mass with respect to 100% by mass of the total amount of the polyester resin, the bis (2-oxazoline) compound and the organic solvent. There is a problem that the adhesion of the coating agent is lowered, and the hot water resistance, chemical resistance, and wet heat durability are poor. On the other hand, when the total amount of the polyester resin and the bis (2-oxazoline) compound exceeds 50% by mass with respect to 100% by mass of the total amount of the polyester resin, the bis (2-oxazoline) compound and the organic solvent, it is obtained. The storage stability of the resulting coating agent is reduced, the viscosity is increased, and the handling property and coating property are inferior. Alternatively, the coating agent may not be obtained because the viscosity becomes too high.

  In the coating agent of the present invention, the equivalent ratio of the oxazolinyl residue of the bis (2-oxazoline) compound to the acid value of the polyester resin needs to be 0.8 to 2.0 times equivalent, and 1.0 to It is preferably 1.8 times equivalent. When the amount is less than 0.8 times equivalent, there are problems that the adhesion of the resulting coating agent is lowered, and that the hot water resistance, chemical resistance, and wet heat durability are poor. On the other hand, when it exceeds 2.0 times equivalent, the storage stability of the resulting coating agent is lowered, the viscosity is increased, and the handling property and coating property are inferior. Alternatively, the coating agent may not be obtained because the viscosity becomes too high.

  Examples of the organic solvent used in the present invention include aromatic solvents such as toluene, xylene, solvent naphtha, and solvesso; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; methyl alcohol, ethyl alcohol, isopropyl alcohol, and isobutyl alcohol Alcohol solvents; ester solvents such as ethyl acetate and normal butyl acetate; acetate solvents such as cellosolve acetate and methoxyacetate. These solvents may be used alone or in combination of two or more. Alternatively, these aqueous solutions may be used.

  In addition, the coating agent of the present invention includes, as necessary, heat stabilizers such as phosphoric acid and phosphate ester, antioxidants such as hindered phenol compounds, hindered amine compounds, and thioether compounds, as long as the effects of the present invention are not impaired. Various additives such as agents, lubricants such as talc, silica and wax, pigments such as titanium oxide, tackifiers such as tackifier, fillers, antistatic agents and foaming agents may be contained.

The manufacturing method of the coating agent of this invention is described below.
The coating agent of the present invention can be produced, for example, by dissolving a polyester resin and a bis (2-oxazoline) compound in an organic solvent by a known method. The method for dissolving the polyester resin and the bis (2-oxazoline) compound in the organic solvent is not particularly limited, but the polyester resin, the bis (2-oxazoline) compound, and the organic solvent are mixed, at room temperature or as required. For example, a method of stirring and dissolving while heating may be used.

  The coating agent of the present invention is applied by a known coating method, and then subjected to a drying step to form the coating film of the present invention. The coating film of the present invention may be directly formed on various base materials. Or a metal vapor deposition layer is previously provided with respect to various base materials, and the coating film may be formed on this metal vapor deposition layer.

  Although it does not specifically limit as a coating method, The method of coating using a coater etc. are mentioned. Examples of the coater include a bar coater, a comma coater, a die coater, a roll coater, a reverse roll coater, a gravure coater, a gravure reverse coater, and a flow coater.

  By adjusting the coating amount of the coating agent at the time of coating, the thickness of the coating film obtained after drying can be arbitrarily controlled. The thickness of the coated film after drying is preferably in the range of 0.1 μm to 20 μm. The temperature in the drying step is preferably in the range of 70 to 150 ° C.

  Examples of the substrate for coating the coating agent of the present invention include films and sheets made of polyester such as polyethylene terephthalate and polycyclohexanedimethyl terephthalate, polycarbonate, acrylic, and inorganic glass plates. Among these, a polyethylene terephthalate film is preferable from the viewpoint of versatility.

  The laminate of the present invention comprises the above-described base material and the coating film of the present invention. Furthermore, the laminated body of this invention may contain the metal vapor deposition layer. By providing a metal vapor deposition layer, a metallic luster can be imparted, so that a decorative effect can be exhibited, and further, a laminate excellent in protection against a substrate is obtained.

  For example, it can be set as the laminated body of this invention by forming the coating film of this invention on the metal vapor deposition layer provided on the base material. By setting it as such a structure, since the coating film excellent in the adhesiveness to a metal vapor deposition layer functions as a protective layer, the expression of the crack in a metal vapor deposition layer can be prevented.

  Or it is good also as a laminated body of this invention by providing the coating film of this invention on a base material as an anchor coat layer as a primer, and forming a metal vapor deposition layer on it. By setting it as such a structure, a metal vapor deposition layer can be stably fixed on a base material. Therefore, it is also possible to obtain a laminate in which a decrease in gas barrier properties is suppressed.

  As a metal vapor deposition layer, the single layer or the multilayer which consists of a metal or a metal oxide is mentioned. Examples of the metal include aluminum, tin, zinc, nickel, manganese, silver, gold, and platinum. Examples of the metal oxide include aluminum oxide and silicon oxide. In order to form these metal deposition layers, a known vacuum deposition method, plasma vapor deposition method, ion plating method, or the like can be used.

  Although the thickness of a metal vapor deposition layer is not specifically limited, It is preferable to set it as 0.01 micrometer-10 micrometers from a viewpoint which provides gas barrier property and metallic luster.

  The laminate of the present invention can be suitably used as various packaging materials having gas barrier properties. Furthermore, it is also possible to form various printing surfaces, laminate adhesive layers, and the like on the surface of the laminate by gravure printing using various printing inks and laminating inks.

  Hereinafter, the present invention will be described more specifically with reference to examples. The present invention is not limited to these examples.

Various physical properties were measured by the following methods.
(1) Copolymerization composition of polyester resin Using a high resolution nuclear magnetic resonance apparatus (manufactured by JEOL Ltd., trade name “JNM-LA400”),
The composition of the polyester resin was determined from the peak intensity of each copolymer component by ¹ H-NMR analysis under the following conditions.
Frequency: 400MHz
Solvent: Deuterated trifluoroacetic acid Temperature: 25 ° C

(2) Weight average molecular weight of polyester resin The weight average molecular weight of polystyrene conversion was measured using gel permeation chromatography (GPC) under the following conditions.
Liquid feeding unit: manufactured by Shimadzu Corporation, trade name “LC-10ADvp”
Ultraviolet-visible spectrophotometer: “SPD-6AV” manufactured by Shimadzu Corporation
Detection wavelength: 254 nm
Column: One “KF-803” manufactured by Shodex and two “KF-804” manufactured by Shodex were connected in series.
Solvent: Tetrahydrofuran

(3) Glass transition temperature of polyester resin According to JIS K-7121, the glass transition temperature was calculated | required using the input compensation type | mold differential scanning calorimeter (made by Perkin-Elmer, brand name "Diamond DSC").

(4) Acid value of polyester resin According to JIS K-0070, 1 g of a sample was dissolved in 50 ml of dioxane at room temperature to obtain a solution. This solution was titrated with a 0.1N potassium hydroxide methanol solution using cresol red as an indicator. And the acid number was calculated | required by calculating the equivalent number contained in 1 ton of polyester resins using the value obtained by titration.

(5) Solubility of polyester resin The concentration of the polyester resin is 30 with respect to each of the mixed solvent of toluene and methyl ethyl ketone [(toluene) / (methyl ethyl ketone) = 50/50, mass ratio] and ethyl acetate. It heated at 55 degreeC and was made to melt | dissolve so that it might become mass%, and the solution was obtained. Thereafter, the solution was allowed to stand for 2 hours in a transparent glass bottle, and then the uniformity was visually confirmed and evaluated according to the following criteria.
(Double-circle): It melt | dissolved uniformly and was a uniform solution even after standing still.
○: Although dissolved uniformly, the solution after standing slightly thickened.
(Triangle | delta): Although melt | dissolved uniformly, the fluidity | liquidity of the solution fell after standing.
X: It did not melt | dissolve even if mixed. Or it dissolved uniformly, but upon standing, it separated or coagulated.
In the present invention, it is necessary that at least one of [(toluene) / (methyl ethyl ketone) = 5/5, mass ratio] of the mixed solvent or ethyl acetate has an evaluation of Δ or more. ○ It is more preferable that the above evaluation be made.

(6) Storage stability of coating agent About 400 g of the coating agent was allowed to stand for 48 hours in a transparent glass bottle. After the static value, the uniformity of the coating agent was visually confirmed and evaluated according to the following criteria.
A: Thickening and layer separation were not uniform.
○: Some thickening was observed, but the layers were not separated and were uniform.
(Triangle | delta): Although the fluidity | liquidity of the solution fell, it was not separating layers but uniform.
X: The layers were separated or solidified.
In the present invention, an evaluation of Δ or more is necessary, but an evaluation of ○ or more is more preferable.

(7) Adhesiveness of coating agent Coating agent obtained in Examples and Comparative Examples using a 38 μm thick polyester film (manufactured by Unitika Ltd., “Emblet”) as a base material and using a bar coater on one side. Was applied. Then, it was made to dry at 110 degreeC for 2 minute (s), the coating film whose film thickness after drying was 15 micrometers was formed, and laminated body (X) was obtained. A copper plate having a thickness of 50 μm was stacked on the surface of the laminate (X) coated with the coating agent, and pressed at 160 ° C. for 1 minute and at a pressure of 0.1 MPa for 1 minute to obtain a laminate (Y). The obtained laminate (Y) was cut to a width of 25 mm, and a 180 ° peel test was performed at 23 ° C. using a tensile strength tester (manufactured by Shimadzu Corporation, “Autograph AG100B”) to measure the peel strength. . The peel strength was converted per 1 cm width and evaluated according to the following criteria.
A: The peel strength was 10 N / cm or more.
A: The peel strength was 5 N / cm or more and less than 10 N / cm.
Δ: The peel strength was 3 N / cm or more and less than 5 N / cm.
X: The peel strength was less than 3 N / cm.

(8) Hot water resistance After the laminate (Y) is left in boiling water for 2 hours, a 180 degree peel test is performed at 23 ° C. using a tensile strength tester in the same manner as (7) above to determine the peel strength. The measured peel strength was converted per 1 cm width and evaluated according to the following criteria.
A: The peel strength was 7 N / cm or more.
A: The peel strength was 5 N / cm or more and less than 7 N / cm.
Δ: The peel strength was 3 N / cm or more and less than 5 N / cm.
X: The peel strength was less than 3 N / cm.

(9) Chemical resistance The laminate (Y) was immersed in an 80% by mass ethanol solution at 25 ° C. for 96 hours. Thereafter, in the same manner as in the above (7), a 180 ° peel test was performed at 23 ° C. using a tensile strength tester to measure the peel strength. The peel strength measured for peel strength was converted per 1 cm width and evaluated according to the following criteria.
A: The peel strength was 7 N / cm or more.
A: The peel strength was 5 N / cm or more and less than 7 N / cm.
Δ: The peel strength was 3 N / cm or more and less than 5 N / cm.
X: The peel strength was less than 3 N / cm.

(10) Wet heat durability The laminate (Y) was subjected to wet heat treatment at 85 ° C x 85% RH. Thereafter, in the same manner as in the above (7), a 180 ° peel test was performed at 23 ° C. using a tensile strength tester to measure the peel strength. The peel strength measured for peel strength was converted per 1 cm width and evaluated according to the following criteria.
A: The peel strength was 7 N / cm or more.
A: The peel strength was 5 N / cm or more and less than 7 N / cm.
Δ: The peel strength was 3 N / cm or more and less than 5 N / cm.
X: The peel strength was less than 3 N / cm.

The polyester resins used in Examples and Comparative Examples were prepared as follows.
(Polyester resin A)
A mixture comprising 332 kg of terephthalic acid, 19 kg of ethylene glycol, 205 kg of 1,2-propanediol and 400 kg of polytetramethylene glycol (molecular weight 1000) (terephthalic acid: ethylene glycol: 1,2-propanediol: polytetramethylene glycol (molecular weight 1000) = 100: 15: 135: 20, molar ratio) was put into a reaction can equipped with a stirring blade, and esterification was performed at 240 ° C. for 5 hours under a pressure of 0.30 MPa while stirring at a rotation speed of 50 rpm.

Thereafter, the obtained esterified product was transferred to a polycondensation can, and 545 g of tetrabutyl titanate monomer (8.0 × 10 ⁻⁴ mol per 1 mol of terephthalic acid) was added as a polymerization catalyst, to 1.3 hPa over 60 minutes. The pressure was gradually reduced until a polycondensation reaction was carried out at 240 ° C. When the weight average molecular weight reached 95800, the decompression was released and the polycondensation reaction was completed. Then, 23 kg of trimellitic anhydride (0.06 mol per mol of terephthalic acid) was added, and the solution was dissolved at 240 ° C. for 2 hours. A polymerization reaction was performed. Thereafter, the pressure was reduced again to 1.3 hPa over 30 minutes, and the reduced pressure was released after maintaining the reduced pressure state of 1.3 hPa for 5 minutes. Then, the resin was dispensed onto the cooled rotating roll, cooled, and sandwiched to obtain a sheet-like polyester resin A. Table 1 shows the charged composition, copolymer composition, and characteristic values of the polyester resin A.

Abbreviations in Table 1 and Table 2 described below indicate the following.
TPA: terephthalic acid IPA: isophthalic acid EG: ethylene glycol NPG: neopentyl glycol PG: 1,2-propanediol PTMG200: polytetramethylene glycol (molecular weight 200)
PTMG650: polytetramethylene glycol (molecular weight 650)
PTMG1000: polytetramethylene glycol (molecular weight 1000)
PTMG2000: Polytetramethylene glycol (molecular weight 2000)
PPG700: Polypropylene glycol (molecular weight 700)
TMA: trimellitic anhydride T / M: mixed solution of toluene and methyl ethyl ketone [(toluene) / (methyl ethyl ketone) = 5/5, mass ratio]
EA: ethyl acetate

(Polyester resins BG, IL and NS)
As shown in Tables 1 and 2, polyester resins B to G, I to L, and N to S were obtained by performing the same operations as for polyester A except that the raw material charge composition was changed. Tables 1 and 2 show the charged composition, copolymer composition, and characteristic values of these polyester resins.

(Polyester resin H)
A mixture comprising 332 kg of terephthalic acid, 12 kg of ethylene glycol, 213 kg of 1,2-propanediol and 260 kg of polytetramethylene glycol (molecular weight 650) (terephthalic acid: ethylene glycol: 1,2-propanediol: polytetramethylene glycol (molecular weight 650) = 100: 10: 140: 20, molar ratio) was put into a reaction can equipped with a stirring blade, and esterification was performed at 240 ° C. for 5 hours under a pressure of 0.35 MPa while stirring at a rotation speed of 50 rpm. .

Thereafter, the obtained esterified product was transferred to a polycondensation can, and 545 g of tetrabutyl titanate monomer (8.0 × 10 ⁻⁴ mol per 1 mol of terephthalic acid) was added as a polymerization catalyst, to 1.3 hPa over 60 minutes. The pressure was gradually reduced until a polycondensation reaction was performed at 245 ° C. When the weight average molecular weight reached 62900, the decompression was released and the polycondensation reaction was completed. Then, 12 kg of trimellitic anhydride (0.03 mol per mol of terephthalic acid) was added, and the solution was dissolved at 240 ° C. for 2 hours. A polymerization reaction was performed. And after discharging resin to a steel belt cooler and cooling, it led to the crusher and grind | pulverized and the flaky polyester resin H was obtained. The copolymer composition and characteristic values of the polyester resin H are shown in Table 1.

(Polyester resin M)
As shown in Table 1, polyester resin M was obtained by performing the same operation as polyester H except that the raw material charge composition was changed. Table 1 shows the charged composition, copolymer composition, and characteristic values of the polyester resin M.

(Polyester resin V)
As shown in Table 2, polyester resin V was obtained by performing the same operation as polyester A except that the raw materials and the charged composition were changed. In the polyester resin V, since the glass transition temperature thereof was less than the range specified in the present invention, it was not solidified even at room temperature and had difficulty in handling and was not used for the preparation of a coating agent. It was.

Example 1
100 parts of polyester resin A, 1,3-bis (2-oxazolin-2-yl) benzene (Mikuni Pharmaceutical Co., Ltd., solid content: 100%, molecular weight 216, oxazolinyl group amount: 9260 equivalents as a bis (2-oxazoline) compound / Ton) (hereinafter sometimes referred to as “1,3PBO”) 7 parts, 0.4 parts of p-toluenesulfonic acid as a crosslinking catalyst, and 251 parts of ethyl acetate as an organic solvent, a paint shaker (Asada A coating agent was prepared by dissolving using “Paint Shaker PC-1290” manufactured by Iron Works. The coating agent was uniformly transparent without layer separation.

(Examples 2-27 and Comparative Examples 1-12)
As shown in Table 3, Table 4, and Table 5, the same as Example 1 except that the type of polyester resin, the type and equivalent ratio of bis (2-oxazoline) compound, the type of organic solvent, and the composition were changed. Operation was performed and the coating agent and the coating film were obtained. However, in Comparative Examples 2, 5, 8 and Comparative Example 12, the solubility of the polyester resin in an organic solvent and the storage stability when used as a coating agent were not good, so the coating agent could not be applied. Various evaluations were not achieved.

なお、表３、表４および表５における１，３ＰＢＯは、１，３−ビス（２−オキサゾリン−２−イル）ベンゼンを示す。

In Tables 3, 4 and 5, 1,3PBO represents 1,3-bis (2-oxazolin-2-yl) benzene.

Abbreviations in Table 4 indicate the following.
1,4PBO: 1,4-bis (2-oxazolin-2-yl) benzene (manufactured by Tokyo Chemical Industry Co., Ltd., solid content: 100%, molecular weight 216, oxazolinyl group amount: 9260 equivalent / ton)
1,4BBON: 1,4-bis (2-benzoxazolyl) naphthalene (manufactured by Tokyo Chemical Industry Co., Ltd., solid content: 100%, molecular weight 362, oxazolinyl group amount: 5525 equivalent / ton)
1,4BPOB: 1,4-bis [2- (5-phenyloxazolyl)] benzene (manufactured by Tokyo Chemical Industry Co., Ltd., solid content: 100%, molecular weight 364, oxazolinyl group amount: 5495 equivalent / ton)
2,5BBOT: 2,5-bis (5-t-butyl-2-benzoxazolyl) thiophene (manufactured by Tokyo Chemical Industry Co., Ltd., solid content: 100%, molecular weight 431, oxazolinyl group amount: 4640 equivalent / ton)

  1,4PB3O in Table 5 is 5,5 ′-(1,4-phenylene) bis (3-oxazoline) (manufactured by Tokyo Chemical Industry Co., Ltd., solid content: 100%, molecular weight 216, oxazolinyl group amount: 9260 equivalent / ton. ).

  As is clear from Tables 3 and 4, the coating agents obtained in Examples 1 to 27 have high adhesion to the base material when subjected to coatings, and are subjected to cold shock treatment and hot water treatment. However, it had sufficient tolerance.

  In the coating agent obtained in Example 2, since the acid value of the polyester resin B used was slightly high, there was room for slight improvement in hot water resistance, chemical resistance and wet heat durability when it was formed into a coating film. Although it was left, it was enough to withstand practical use.

  In the coating agent obtained in Example 4, since the weight average molecular weight of the polyester D used was slightly high, there was still room for improvement in the storage stability of the coating agent. Could withstand.

  In the coating agent obtained in Example 5, since the acid value of the polyester resin E used was somewhat low, there was room for improvement in adhesion when it was made into a coating film. Can withstand practical use.

  In the coating agent obtained in Example 7, since the molecular weight of the polyester G used was slightly low, there was room for slight improvement in chemical resistance when it was formed into a coating film. It could withstand practical use.

  In the coating agent obtained in Example 13, since the molecular weight of the polyoxyalkylene glycol in the polyester M used was somewhat low, there was room for slight improvement in wet heat durability when it was formed into a coating film. However, it was sufficiently practical.

  In the coating agent obtained in Example 14, since the acid value of the polyester resin B used was slightly high, there was room for slight improvement in hot water resistance, chemical resistance and wet heat durability when formed into a coating film. Although it was left, it was enough to withstand practical use.

  In the coating agent obtained in Example 15, since the acid value of the polyester resin E used was somewhat low, there was still a room for improvement in adhesion, but it was sufficiently practical. It was a thing.

  In the coating agent obtained in Example 25, the total of the polyester resin and the bis (2-oxazoline) compound is slightly larger than the total of the polyester resin, the bis (2-oxazoline) compound and the organic solvent. there were. For this reason, there was room for slight improvement in the storage stability of the coating agent, but it was sufficiently practical.

  In the coating agent obtained in Example 27, since the acid value of the polyester U used was slightly low, there was room for slight improvement in hot water resistance, chemical resistance and wet heat durability when formed into a coating film. Although it was a thing, it was able to endure practically enough.

  In the coating agent obtained in Comparative Example 1, polyester resin N having an acid value exceeding 895 equivalent / ton was used. Therefore, the coating agent is inferior in hot water resistance, chemical resistance and wet heat durability when formed into a coating film.

  In the coating agent obtained in Comparative Example 2, polyester resin O having a weight average molecular weight exceeding 40,000 was used. For this reason, the solubility of the polyester resin in an organic solvent is reduced, and a coating agent cannot be produced.

  In the coating agent obtained in Comparative Example 3, a polyester R resin having a weight average molecular weight of 10,000 or less was used. Therefore, the coating agent is inferior in chemical resistance when formed into a coating film.

  In the coating agent obtained in Comparative Example 4, a polyester resin P having an acid value of less than 35 equivalents / ton was used. Therefore, this coating agent was inferior to the adhesiveness when it was set as the coating film.

  In the coating agent obtained in Comparative Example 5, the proportion of the polyoxyalkylene glycol in the entire polyester component in the polyester resin Q used exceeded 30 mol%. For this reason, the solubility of the polyester resin in an organic solvent is reduced, and a coating agent cannot be produced.

  Since the coating agent obtained in Comparative Example 6 does not contain polyoxyalkylene glycol, polyester resin S having a glass transition temperature of 50 ° C. or higher was used. Therefore, the coating agent is inferior in wet heat durability when formed into a coating film.

  The coating agent obtained in Comparative Example 7 is an oxazoline compound other than the bis (2-oxazoline) compound (5,5 ′-(1,4-phenylene) bis (3-oxazoline)) (in the table, “ 1,4PB3O ") was used as a crosslinking agent. For this reason, the coating agent is inferior in adhesion, hot water resistance, chemical resistance and wet heat durability when formed into a coating film.

  In the coating agent obtained in Comparative Example 8, the amount of terminal groups of the bis (2-oxazoline) compound contained exceeded 2.0 times equivalent to the acid value of the polyester resin. For this reason, the storage stability of the coating agent is lowered, and the coating agent cannot be produced.

  In the coating agent obtained in Comparative Example 9, the amount of terminal groups of the bis (2-oxazoline) compound contained was less than 0.8 times equivalent to the acid value of the polyester resin. For this reason, the coating agent is inferior in adhesion, hot water resistance, chemical resistance and wet heat durability when formed into a coating film.

  The coating agent obtained in Comparative Example 10 did not contain a bis (2-oxazoline) compound. For this reason, the coating agent is inferior in adhesion, hot water resistance, chemical resistance and wet heat durability when formed into a coating film.

  In the coating agent obtained in Comparative Example 11, the total of the polyester resin and the bis (2-oxazoline) compound is 100% by mass with respect to the total amount of the polyester resin, the bis (2-oxazoline) compound and the organic solvent. It was less than 5% by mass. Therefore, the coating agent is inferior in adhesion, hot water resistance, chemical resistance and wet heat durability when it is formed into a coating film.

  In the coating agent obtained in Comparative Example 12, the total of the polyester resin and the bis (2-oxazoline) compound is 100% by mass with respect to the total amount of the polyester resin, the bis (2-oxazoline) compound and the organic solvent. Over 50% by mass. For this reason, the storage stability of the coating agent is lowered, and the coating agent cannot be produced.

Claims (3)

Containing polyester resin, bis (2-oxazoline) compound and organic solvent in which aromatic dicarboxylic acid is copolymerized at a ratio of 60 mol% or more with respect to all carboxylic acid components, with dicarboxylic acid component and glycol component as main components And a coating agent characterized by simultaneously satisfying the following (i) to (vi):
(I) The polyester resin contains 2 to 30 mol% of a polyoxyalkylene glycol having a molecular weight of 200 to 2000 represented by the following formula (I) as a glycol component.

In formula (I), n is an integer of 2 to 36, and m is an integer of 2 to 200.
(Ii) The weight average molecular weight of the polyester resin is more than 10,000 and not more than 40,000.
(Iii) The glass transition temperature of the polyester resin is −35 ° C. or higher and lower than 50 ° C.
(Iv) The acid value of the polyester resin is 35 to 895 equivalent / ton.
(V) The equivalent ratio of the oxazolinyl residue of the bis (2-oxazoline) compound to the acid value of the polyester resin is 0.8 to 2.0 times equivalent.
(Vi) The content ratio of the polyester resin, the bis (2-oxazoline) compound and the organic solvent is [polyester resin + bis (2-oxazoline) compound] / (organic solvent) = 5/95 to 50/50 by mass ratio. It is. Coating film characterized by comprising formed from the coating agent according to claim 1 Symbol placement. A laminate comprising a substrate and the coating film according to claim 2 .